1. Field of the Invention
This invention relates to a film cassette for storing light sensitive, heat developable film.
2. Description of the Prior Art
The use of light sensitive, heat developable film is known in the prior art even though it does not have a wide spectrum of application. Dry silver film of that nature is available from the Minnesota Mining and Manufacturing Company. It is normally supplied in wide widths on relatively large reels.
The patent literature discloses some applications of heat developable film in the contact of laser scanners. See, the example, U.S. Pat. No. 3,631,415. U.S. Pat. No. 3,535,684 discloses a heat developable film strip used in the context of a non-holographic, flying spot scanner. Similarly, U.S. Pat. No. 3,887,787 discloses the use of a scanner beam with a film strip in the context of a heater/ developer system. U.S. Pat. No. 4,116,559 is of special interest in that it discusses a variety of prior art heater structures for use with heat developable film. The following U.S. Patents are also of interest, though of less direct relevance: U.S. Pat. Nos. 3,655,256; 4,076,536 and 4,346,880.
One of the more important features of the present invention is the ability to manipulate a latch, or a lid associated with a film cassette. U.S. Pat. No. 4,033,523 is relevant in that it discloses a cassette having a cover including a latch mechanism which automatically disengages once the cassette is placed into the camera. U.S. Pat. No. 3,865,238 appears to have similar structure and was cited in the prosecution of U.S. Pat. No. 4,033,523. Less relevant, but also cited in the prosecution of U.S. Pat. No. 4,033,523 was U.S. Pat. No. 3,401,899. U.S. Pat. No. 4,116,559, previously discussed, is of possible relevance in that it discloses the combination of a film package with a heater element. Also, U.S. Pat. No. 3,249,033 is of note in that it discloses the use of a cassette in the context of a light fixed medium.
The prior art also discloses cassette type structures of possible relevance. For example, U.S. Pat. No. 3,939,975 describes a structure which allows a film loop or the like to be pulled outside of a housing. U.S. Pat. No. 4,422,550 shows a housing having a pivot-up type of front door. Similar pivot-up front doors are known to be used with modern video cassette recorders. U.S. Pat. No. 4,021,006 describes a film cassette structure having a set of jaws that operate as doors. Of lesser note is U.S. Pat. No. 3,934,270 which discloses a system employing a pair of motors to drive the supply and take-up reels and in which the speed of the film is controlled by a separate capstan drive mechanism. Lastly, U.S. Pat. No. 4,457,473 discloses a mechanism in which the supply and take-up reel are driven by a belt that contacts the edge of both film reels. In addition to the foregoing there are a variety of mechanisms known in the video tape recording art for extracting a loop of film from a cassette housing so that it can come into contact with a read and/or write mechanism.
Other patents of interest, but less relevance, include: U.S. Pat. Des. 195,909; Des. 199-649; Des. 210,172; Des. 208,216 Des. 244,943; Des. 231,993; U.S. Pat. Nos. 3,526,884; 3,467,339; 4,136,839.
Insofar as understood, none of the prior art discloses a cassette for use with light sensitive, heat developable film in which a light tight door is operable to allow a film carrier to automatically extend beyond the housing of the cassette.